The invention relates to an arrangement in the on-line finishing of a paper machine, which includes at least one finishing stage (12, 13) for the paper web produced with the paper machine, and which arrangement includes                cutting equipment (16) prior to the finishing stage (12, 13) for forming a tail from a fully wide paper web,        tail threading equipment (15) for taking the formed tail through the finishing stage (12, 13), and        a draw point (24) at the end of the finishing stage (12, 13) for tensioning and holding the paper web in the finishing stage (12, 13),with the carrier rope system (17) included in the said tail threading equipment (15) being adapted to pass by the draw point (24).        
Today in paper machines, the tendency is to locate the finishing line immediately after the production line in order to improve efficiency. This means that the paper web is immediately guided to the finishing process from the last section of the production line without intermediate reeling and a separately located finishing line. In other words, the paper web runs at the production speed during finishing, and therefore the term on-line finishing is also used. Normally finishing includes coating of the paper. To produce an optimum quality paper, the paper web is first precalendered in the finishing process in order to ensure successful coating. Finally the coated paper is often also calendered, which provides a good surface smoothness and gloss, for example, to the coated paper.
The paper web is taken through the various finishing stages by means of a tail formed out of the paper web. The tail also proceeds at the production speed. Consequently, particularly the speed differences between the various tail threading devices often cause a tail threading failure. In addition, the paper web is spread to the full width between the different finishing stages prior to starting the following tail threading procedure. In present applications the tail must be taken, for example, through the coating process and spread to the full width before the paper web can be measured in respect of precalendering. Consequently, controlling of the various finishing stages is indefinite and awkward because the reliability of the effect of the various finishing stages is uncertain. Furthermore, in the situation described above, the coated paper needs to be guided to broke treatment during the precalendering adjustment. This increases the consumption of the coating material and complicates the broke treatment.
Adjustment problems are also created in tail threading because the tail needs to be guided for a long distance. This makes the tail stretch and even break sometimes Also the speed differences between the various tail threading devices and finishing devices lead to tail breaking, in which case the tail threading procedure must be usually started over again. Particularly in the present paper machines the tail threading devices are provided with speed sensors. In practice, however, controlling the speed of the tail threading devices and a sufficiently accurate speed measurement are difficult and sometimes even impossible. With the further increasing speed, the problems become even worse. Normally the tail is transferred through the finishing stage by means of ropes. The finishing stage often ends at a drying unit, which comprises dryer cylinders and a dryer wire. When arriving at the drying unit with the carrier rope system, the tail tends to move onto the dryer wire if even a slight speed difference is present. In this situation the tail normally breaks and tail threading fails. At the same time, parts of the tail remain in the drying unit, which may disturb the following tail threading attempts.
The tail is usually formed out of the paper web using water cutters, which are arranged in connection with the drying units. As the paper web must be cut against the dryer wire, cuttings gradually block the dryer wire. Cuttings also spread into the drying unit and, in the worst case, to the entire finishing process following it. This increases the likelihood of web breaks and impairs the quality of the final product.
Furthermore, various kinds of cleaning devices are required.
U.S. Pat. No. 4,728,396 sets forth a coater and a method for using it. In this method the web is guided to the broke pit at the full web width after unreeling the paper reel. A tail is separated from the web, and this tail is guided to the coating device. After spreading the tail, coating is started. At a web break, the web is led to the broke pit at the processing speed and the tail threading procedure is repeated. The equipment in question is a so-called off-machine coater. In addition, there is low potential in contributing to a successful tail threading.